Memory cards for storing data are used in many electronic devices, such as video cameras, digital still cameras, smartphones, PDA's, music players, ATMs, cable television decoders, toys, games, PC adapters, multi-media cards and other electronic applications. A card reader, which typically is part of an electronic device, is used to read data from a memory card and transmit the data to the electronic device. And a card reader may also be used to write data from the electronic device to the memory card. A card connector is used to connect a memory card to a card reader.
There are a variety of card connectors. A common type of card connector is the push-push type, in which a memory card is first pushed into the cavity of the card connector to a latched operative position and is pushed again to be ejected and released from the latched position.
U.S. Pat. No. 7,367,828 ('828 patent), incorporated herein by reference, describes a typical memory card connector of the push-push type. As illustrated in FIGS. 1, 2 and 5-10 of this patent, a memory card connector 26 includes a dielectric housing 28 and a sheet metal shell 30. The housing 28 and metal shell 30 together define a cavity 32 for receiving a memory card 36 (FIG. 5). The cavity 32 has a front insertion opening 34 for a memory card to be inserted into and removed from the cavity 32. Referring to FIGS. 3 and 4, the rear section 28a of the housing 28 has through passages 38 for mounting a plurality of terminals 58 for connecting the memory card to a card reader.
Referring to FIG. 1 of the '828 patent, the memory card connector 26 also includes a card sliding member mechanism 60 located within the housing 28. The card sliding member mechanism 60 includes a cam slider (a sliding member) 62, a pin 64 and a coil spring 66. The coil spring 66 is mounted on a spring mounting post 48 (FIG. 3) and is sandwiched between the cam slider 62 and a rear wall portion 42b.
Referring to FIGS. 1 and 14 of the '828 patent, the cam slider 62 includes a rear, upwardly projecting body block 62a and a forwardly projecting locking arm 62b. The distal end of the locking arm 62b includes a locking projection 68, which has a gentle sloping surface 68a at the lead side of the projection and an abrupt catch surface 68b at the rear of the projection 68. The cam slider 62 also includes a heart-shaped cam slot 70 on an outside face 62c of the locking arm 62b. The heart-shaped cam slot 70 is of a conventional “push/push” configuration.
As shown in FIG. 1 of the '828 patent, a first end 64a of the pin 64 is fixed to a side wall section 28b of the housing 28. A second end 64b of the pin 64 is captured in the heart-shaped cam slot 70. Therefore, the second end 64b of the pin 64 follows the contour of the cam slot 70. The coil spring 66 constantly urges the cam slider 62 in a forward direction toward the front insertion opening 34 of the card-receiving cavity 32.
FIGS. 15-18 of the '828 patent show how the memory card 36 is inserted into the card-receiving cavity 32 through the front insertion opening 34 and placed in the latched operative position. As shown in FIG. 15, the memory card 36 is inserted into the cavity 32 in the direction of the arrow designed by “A.” In FIG. 15, the memory card 36 is at a point where the memory card 36 rides along the gentle sloped surface 68a (FIG. 14) of the locking projection 68 to bias the locking projection 68 and the locking arm 62b downwardly.
FIG. 16 shows the memory card 36 being inserted further in the direction of arrow “A” until the locking projection 68 of the locking arm 62b snaps into a locking recess 36b at the edge of the memory card 36, where the contacts on the underside of the memory card 36 are in contact with the terminals 58 (FIG. 11). The memory card 36 now is locked to the cam slider 62 so that the memory card 36 and cam slider 62 move together.
FIG. 17 of the '828 patent shows the memory card 36 and cam slider 62 being pushed all the way inwardly to an “overrun” or inner limit position. At this position, the memory card 36 and cam slider 62 further compress the coil spring 66.
When pushing of the memory card 36 in the inward direction “A” is stopped, as shown in FIG. 18, the coil spring 66 pushes the memory card 36 and cam slider 62 back outwardly until the second end 64b of the pin 64 latches into a latch notch 70a (FIG. 14) of the heart-shaped cam slot 70 and the memory card 36 and cam slider 62 are stopped at the latched operative position. At this point, the contact portions 58e of the terminals 58 are still engaged with the contacts on the underside of the memory card 36.
From the latched operative position, a further push (to the “overrun” or inner limit position) and a release of the memory card 36 allow the coil spring 66 to push the memory card 36 back to the position of FIG. 16, whereupon the memory card 36 can be pulled outwardly with the locking recess 36b riding over the catch surface 68b (FIG. 14) of the locking projection 68.
Throughout this entire process, the spring arm 84 (FIGS. 2 and 7) which is stamped and formed out of a side plate 30b of the metal shell 30, is effective to bias the pin 64 into the heart-shaped cam slot 70 of the cam slider 62.
Although not described in the '828 patent, the lock of the projection 68 of the locking arm 62b with the recess 36b of the memory card 36 can be either a soft lock or a hard lock. In a soft lock, the lock of the projection 68 with the recess 36b can prevent accidental removal of the memory card 36 from its latched operative position. But it cannot prevent the memory card 36 from being forcefully pulled out from its latched operative position. In a hard lock, the lock of the projection 68 with the recess 36b can prevent the memory card 36 from being pulled out either by accident or by the application of a force.
FIGS. 1A and 1B of the present application are schematic drawings of a hard lock between a projection 68 and a recess 36b of the memory card 36. The configuration of the projection 68 prevents the memory card 36 from being removed when the projection 68 is engaged with the recess 36b.